Wet cell storage batteries contain a plurality of individual cells closed by individual caps. Such batteries fall into two categories, the first category employing caps which are designed to be removable, the second category employing caps which are sealed and are not normally removable.
In order to monitor the condition of batteries in the first category to determine whether the battery is in good condition or needs replacement, it is known to remove the cap of each cell to check and replenish the electrolyte level as needed and also to measure the specific gravity of the electrolyte. If all cells as tested individually are found to be in good condition, the battery will function properly; if one or more cells are found not to be in good condition, the battery should be replaced.
In order to monitor the condition of batteries in the second category, the electrolyte level and specific gravity of the electrolyte in each cell cannot be measured separately because of the sealed cap.
The present invention is directed toward apparatus for monitoring the condition of batteries in the second category by making use only of the positive and negative battery terminals.